medwireNews: Children receiving continuous subcutaneous insulin infusion (CSII) achieve better long-term glycated haemoglobin (HbA1c) levels than those relying on multiple daily injections, shows a registry study.

After an initial fall, HbA1c increased over time in both groups but, at all ages, it remained lower among pump-treated patients than those using multiple injections, report Birthe Olsen (Herlev University Hospital, Denmark) and study co-authors in Pediatric Diabetes.

The researchers acknowledge that a registry study is an open and uncontrolled design. “However, it demonstrates the efficacy and safety of CSII in a large population under real-life conditions”, they say, and contradicts previous studies that failed to show a sustained benefit.

The study included 3339 patients with Type I diabetes who were followed up for an average of 5.11 years, during which time 1493 patients switched from multiple injections to CSII.

Overall, HbA1c levels rose with age; levels relative to those above age 15 years were 4.31 mmol/mol lower at age 0 to 5 years but just 2.69 mmol/mol lower at age 10 to 15 years. Nonetheless, the average level remained a significant 5.29 mmol/mol higher in patients receiving injections than those who switched to a pump for all age groups.

Among patients using pumps, the association between HbA1c and age disappeared after adjusting for diabetes duration and age at onset.

After accounting for confounders, a lower HbA1c level at pump initiation was associated with a lower level during follow-up, as was a more recent age at onset and treatment at a centre with more than 100 CSII patients.

A higher number of self-monitoring of blood glucose measurements was also independently associated with a lower HbA1c level. During follow-up, many patients receiving injections who were taking two daily doses of premixed insulin switched to a basal/bolus insulin regimen. Among these patients, a higher number of daily insulin boluses and a higher percentage of insulin taken as bolus were also independently associated with a lower HbA1c level.

However, the researchers note that there were no further improvements above five daily boluses and 45 weekly glucose measurements. And they also note: “As might be expected, compliant patients seem to obtain the best metabolic control.”

By Eleanor McDermid, Senior medwireNews Reporter

Pediatr Diabetes 2014; Advance online publication

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